 /*******************************************************************************
  * Copyright (c) 2003, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM - Initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.runtime.jobs;

 /**
  * Scheduling rules are used by jobs to indicate when they need exclusive access
  * to a resource. Scheduling rules can also be applied synchronously to a thread
  * using <tt>IJobManager.beginRule(ISchedulingRule)</tt> and
  * <tt>IJobManager.endRule(ISchedulingRule)</tt>. The job manager guarantees that
  * no two jobs with conflicting scheduling rules will run concurrently.
  * Multiple rules can be applied to a given thread only if the outer rule explicitly
  * allows the nesting as specified by the <code>contains</code> method.
  * <p>
  * Clients may implement this interface.
  *
  * @see Job#getRule()
  * @see Job#setRule(ISchedulingRule)
  * @see Job#schedule(long)
  * @see IJobManager#beginRule(ISchedulingRule, org.eclipse.core.runtime.IProgressMonitor)
  * @see IJobManager#endRule(ISchedulingRule)
  * @since 3.0
  */
 public interface ISchedulingRule {
     /**
      * Returns whether this scheduling rule completely contains another scheduling
      * rule. Rules can only be nested within a thread if the inner rule is completely
      * contained within the outer rule.
      * <p>
      * Implementations of this method must obey the rules of a partial order relation
      * on the set of all scheduling rules. In particular, implementations must be reflexive
      * (a.contains(a) is always true), antisymmetric (a.contains(b) and b.contains(a) iff a.equals(b),
      * and transitive (if a.contains(b) and b.contains(c), then a.contains(c)). Implementations
      * of this method must return <code>false</code> when compared to a rule they
      * know nothing about.
      *
      * @param rule the rule to check for containment
      * @return <code>true</code> if this rule contains the given rule, and
      * <code>false</code> otherwise.
      */
     public boolean contains(ISchedulingRule rule);

     /**
      * Returns whether this scheduling rule is compatible with another scheduling rule.
      * If <code>true</code> is returned, then no job with this rule will be run at the
      * same time as a job with the conflicting rule. If <code>false</code> is returned,
      * then the job manager is free to run jobs with these rules at the same time.
      * <p>
      * Implementations of this method must be reflexive, symmetric, and consistent,
      * and must return <code>false</code> when compared to a rule they know
      * nothing about.
      *
      * @param rule the rule to check for conflicts
      * @return <code>true</code> if the rule is conflicting, and <code>false</code>
      * otherwise.
      */
     public boolean isConflicting(ISchedulingRule rule);
 }

